Track structure for railborne vehicles, particularly trains

ABSTRACT

A track structure for railborne vehicles comprising a bed on which rails fastened to sleepers are seated. The structure comprises a concrete trough seated on a substructure and having walls extending in the longitudinal direction. The side walls are spaced apart parallel to one another at least by a sleeper length. A method of manufacturing of the structure is also provided.

FIELD OF INVENTION

The invention relates to a track structure for railborne vehicles,particularly trains, comprising a bed on which rails fastened tosleepers are seated.

BACKGROUND DESCRIPTION

A ballast bed, which generally consists of weather-resistant hard rock(for example basalt) in various particle sizes depending on the trackloading, is first formed for this track structure. The standard depth ofballast to the bottom edge of the sleeper is 30 cm. Rails or railsections connected to concrete or wooden sleepers are placed on thisballast bed. Track-tamping machines are used to push ballast under thesleepers. These machines are equipped with hydraulically controlledpicks which press the ballast under the sleepers. In order to allowrainwater to flow off and to prevent the rails lying under water, theballast bed has to be regularly cleared of foreign matter. For thispurpose, the ballast has to be lifted up, screened and then placed backon the track bed. It then has to be tamped again. Laying the rails andmaintaining the track bed are therefore time-consuming andcost-intensive operations.

SUMMARY OF THE INVENTION

Taking this problem as the departure point, the intention is to improvethe track structure described at the beginning such that the railsections can be laid in a simple and cost-effective manner and the timerequired for maintenance work is reduced. In addition, the trackstructure should ensure maximum noise reduction.

To solve the problem, the generic track structure is distinguished bythe fact that the bed consists of a concrete trough seated on asubstructure and having side walls extending in the longitudinaldirection, and by the fact that the side walls are spaced apart parallelto one another at least by the sleeper length.

This design makes it possible to dispense completely with the ballastbed. The side walls take over the lateral retention of the sleepers.Laying the rail sections is considerably simplified because they haveonly to be fitted into the concrete trough. Tamping is dispensed withcompletely. Foreign matter accumulating over time can be removed simplyby suction. Maintenance work can thus be carried out in a substantiallysimple and cost-effective manner. It should be assumed with regard tothis track structure that lightweight materials, such as, for example,leaves, are automatically removed from the track bed by the suctionaction of fast-moving trains. Moreover, the maintenance intervals areextended even further as a result. Worn or damaged rail parts can bereplaced in a simple manner.

The substructure is preferably cast in situ from lightweight concrete,in particular foamed concrete. Expansion joints are not absolutelynecessary. The concrete trough preferably consists of steel-reinforcedfoamed concrete. Foamed concrete is also referred to as cellularconcrete. The steel-reinforced concrete trough is placed on thesubstructure. If appropriate, it may be laterally covered with soil. Theuse of foamed concrete affords high sound-absorbing values, therebyreducing the noise generated by trains as they move past.

The substructure has a density of 400-650 kg/m³, particularly preferably450 kg/m³. The concrete trough preferably has a density of 1100-1900kg/m³, in particular 1500 kg/m³.

Having the rails protrude beyond the side walls in the verticaldirection ensures that the rail surface is freely accessible to trafficeven when there are considerable amounts of precipitation and that thevehicle wheels do not travel through accumulated water.

If the parallel spacing between the side walls corresponds to thesleeper length, the rail sections are automatically centered uponfitting.

To ensure that rainwater or melt water can be quickly drained from thetrack structure, the side walls of the concrete trough are preferablyprovided with a multiplicity of wall openings into which pipes areparticularly preferably inserted.

At least one empty pipe is integrated into the substructure so thatsupply lines or the like can be laid at some later time.

It is particularly advantageous if the concrete trough consists ofindividual prefabricated segments which can be placed on thesubstructure produced in situ and connected to one another. Theproduction of the track structure is thus further simplified and theconstruction time further reduced. Moreover, individual segments may beeasily replaced if required, thereby reducing the maintenance costs.

To enable the individual segments to be aligned with one another andfixed laterally, the base of each segment is provided at its ends with acentral slot or a cutout into which can be fitted an insert which ispreferably T-shaped in cross section. This insert prevents the segmentsfrom drifting apart laterally.

The method of producing a track structure for railborne vehicles,particularly trains, is distinguished by the following steps:

-   -   a) casting a substructure from a lightweight concrete, in        particular a foamed concrete having a (dry) density of 400-700        kg/m³;    -   b) placing prefabricated trough segments on the substructure to        form a concrete trough having side walls extending in the        longitudinal direction;    -   c) aligning the trough segments with one another;    -   d) fitting rail sections fastened to sleepers between the side        walls.

Inserts are preferably fitted into central slots provided in the base ofthe trough segments to center the segments and secure the butt jointagainst lateral displacement.

BRIEF DESCRIPTION OF THE DRAWINGS

An exemplary embodiment of the invention will be described in moredetail below with the aid of a drawing, in which:

FIG. 1 shows a perspective view of the track structure;

FIG. 2 shows the plan view of a track structure;

FIG. 3 shows a partial representation of the concrete trough in thedirection of view arrow III according to FIG. 2;

FIG. 4 shows an insert in a perspective representation;

FIG. 4 a shows a further insert in a perspective representation;

FIG. 5 shows the section along the line V-V according to FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

The track structure consists of the substructure 5, which is cast insitu from lightweight concrete, in particular foamed concrete, asproduced for example by the Canadian company Cematrix. Standardshuttering is necessary for this purpose. The foamed concrete can bemixed in situ. Foaming is induced using bubble-forming substances(blowing in air). Integrated into the substructure 5 is at least oneempty pipe 6 through which supply lines can be drawn at some later time.The substructure 5 is provided with slightly upwardly extended sidewalls 5 a, 5 b. The use of foamed concrete is common in roadbuilding.Foamed concrete is distinguished by good sound-absorbing properties andhigh thermal insulation.

Prefabricated segments S consisting of reinforced concrete are fittedbetween the side walls 5 a, 5 b. A plurality of segments S laid againstone another form a concrete trough 4 having a base 4 c and the sidewalls 4 a, 4 b which point in the vertical direction. The width of thesegment S is chosen so that it can be fitted exactly between the sidewalls 5 a, 5 b of the substructure 5, thereby preventing lateraldisplacement of the concrete trough 4. The segments (S) are produced ina length of 5-15 m.

A multiplicity of openings 7 into which pipes are inserted are providedin the side walls 4 a, 4 b of each segment 4, thereby allowing waterwhich accumulates in the trough 4 to run off to the outside. The segmentS is provided at both its ends with a cutout or a slot 9 which isarranged centrally in the base 4 c. An insert 8 of T-shaped crosssection can be fitted into this cutout 9. Two abutting segments S arealigned with one another and fixed laterally via this insert 8, therebymaking it possible for the butt joint to be secured. The butt joint canbe better secured using the insert 8′ of cruciform cross section shownin FIG. 4 a. The additional leg 8″ can be driven into or inserted intothe substructure 5.

The prefabricated segments S are placed individually on the substructure5 so that they adjoin one another. Rail sections 1, 2 fastened toconcrete or wooden sleepers 3 are fitted into the concrete trough 4. Theinside dimension between the side walls 4 a, 4 b of the trough 5corresponds to the length L of the sleepers 3, with the result that theconcrete trough 4 is responsible for laterally guiding the rail sections1, 2.

As can be observed from FIG. 5, the side walls 4 a, 4 b of the trough 4are designed to be somewhat higher than the thickness of the sleepers 3,with the result that the sleepers are sunk completely into the trough,whereas the rail sections 1, 2 fastened to the sleepers 3 protrudebeyond the trough 4. Soil 10 which covers the substructure 5 is piledlaterally against the trough 4.

The substructure 5 preferably consists of nonreinforced lightweightconcrete having a density of 400-700 kg/m³. Good results have beenobtained with a density of 450 to 650 kg/m³. The trough 4 consists ofreinforced concrete comprising galvanized reinforcement and having adensity of 1100-1900 kg/m³, good results having been achieved with adensity of 1500 kg/m³.

LIST OF REFERENCES

-   1 rail/rail section-   2 rail/rail section-   3 sleeper-   4 concrete trough/trough-   4 a side wall-   4 b side wall-   4 c base-   5 substructure-   5 a side wall-   5 b side wall-   6 empty pipe-   7 opening-   8 insert-   8′ insert-   8″ leg-   9 slot/cutout-   10 soil-   L sleeper length-   S segment

1. A track structure for railborne vehicles comprising a bed on whichrails fastened to sleepers are seated, the bed comprising a concretetrough seated on a substructure and having side walls extending in alongitudinal direction, and the side walls are spaced apart parallel toone another at least by a sleeper length, wherein the rails protrudebeyond the side walls in a vertical direction, the concrete troughcomprises steel-reinforced foamed concrete, the side walls are higherthan the sleepers, the substructure has a density of 400-700 kg/m³, andthe concrete trough has a density of 1100-1900 kg/m³.
 2. The trackstructure as claimed in claim 1, wherein the side walls are providedwith a multiplicity of wall openings.
 3. The track structure as claimedin claim 1, wherein the sleepers contact the concrete trough.
 4. A trackstructure for railborne vehicles comprising a bed on which railsfastened to sleepers are seated, the bed comprising a concrete troughseated on a substructure and having side walls extending in alongitudinal direction, and the side walls are spaced apart parallel toone another at least by a sleeper length, wherein the concrete troughincludes individual segments, and a base of each segment is provided atboth ends with a central slot or a cutout, further comprising an insertfitted into the slot to center the segments, wherein the insert isT-shaped in cross section.
 5. A method of producing a track structurefor railborne vehicles comprising: a) casting a substructure from alightweight concrete; b) placing prefabricated trough segments on thesubstructure to form a concrete trough having side walls extending in alongitudinal direction; c) aligning the trough segments with oneanother; and d) fitting rail sections fastened to sleepers seated on andcontacting the concrete trough and between the side walls of theconcrete trough, further comprising fitting inserts into central slotsin a base to center the segments and secure a butt joint against lateraldisplacement.
 6. The method as claimed in claim 5, wherein the castingof the substructure is from foamed concrete having a (dry) density of400-700 kg/m³.
 7. The method as claimed in claim 5, wherein a spacingbetween the side walls of the concrete trough corresponds to a length ofthe sleepers.
 8. The method as claimed in claim 5, wherein the railsprotrude beyond the side walls in a vertical direction.
 9. The method ofclaim 5, wherein the side walls are higher than the sleepers such thatthe sleepers are sunk completely into the concrete trough.
 10. Themethod of claim 5, wherein the substructure comprises upwardly extendingside walls that prevent lateral displacement of the concrete trough. 11.A method of producing a track structure for railborne vehiclescomprising: a) casting a substructure from a lightweight concrete; b)placing prefabricated trough segments on the substructure to form aconcrete trough having side walls extending in a longitudinal direction;c) aligning the trough segments with one another; and d) fitting railsections fastened to sleepers seated on and contacting the concretetrough and between the side walls of the concrete trough, wherein a baseof each segment is provided at both ends with a central slot or acutout.
 12. The method as claimed in claim 11, further comprising aninsert fitted into the slot to center the segments.
 13. The method asclaimed in claim 12, wherein the insert is T-shaped in cross section.14. A track structure for railborne vehicles comprising a bed on whichrails fastened to sleepers are seated, the bed comprising a concretetrough seated on a substructure and having side walls extending in alongitudinal direction, and the side walls are spaced apart parallel toone another at least by a sleeper length, wherein the rails protrudebeyond the side walls in a vertical direction, the concrete troughcomprises prefabricated trough segments which are aligned with oneanother, the substructure comprises a lightweight foamed concrete andhas a density of 400-700 kg/m³, the concrete trough has a density of1100-1900 kg/m³, and the trough segments include fitted inserts in slotsat both ends to center the trough segments and secure a butt jointagainst lateral displacement.
 15. The track structure as claimed inclaim 14, wherein the insert is T-shaped in cross section.
 16. The trackstructure as claim 14, wherein the trough segments are steel reinforced.